Raid Passes are items that can be acquired by spinning the Photo Disc at a Gym. They are used by trainers to participate in Raid Battles. Raid Passes can be obtained by Trainers on Level 5 and above, because of Trainer has not access to Gyms before Level 5.
There are three types of these passes:
regular Raid Pass,
Premium Raid Pass
and EX Raid Pass.
To see currently owned Raid Passes player can check them out on the item bag page .
The method for obtaining one is currently unknown because this feature is undergoing beta-tested. Select Trainers will receive an EX Raid Pass via their Journal. When the user clicks on the item in the journal, an invitation will be presented and provide information as to when and where the the EX Raid Battle will occur.
Many reports indicate that the chosen Gym will be one that has been recently raided by the Trainer in the past couple of days.
In-game description EX Raid Pass to join a field test for a special Raid Battle. You can use this pass only at the specified limited-time event.